Evaluation of water content in transformer paper insulation based on recovery voltage analysis

The article presents the results of recovery voltage measurements on test transformers that are located in the Institute of Electrical Power Engineering, Poznan University of Technology (the transformers are date back from the sixties, the seventies and the eighties). Simultaneously, the polarization index R"/Ri5 was determined and compared with RVM results. All presented results were obtained using the automatic recovery voltage meter, 5462 type, manufactured by Tettex Instruments.